<?php

echo ceil(898.4354);

echo "<br>";

echo floor(5675645.56);

echo "<br>";

echo round(6787.4565,2);

echo "<br>";

echo max(67,67,6,7,67,6,76);

echo "<br>";

echo min(67,67,6,7,67,6,76);

echo "<br>";

echo rand(5,10);

echo "<br>";
echo mt_rand(1,47);

echo "<br>";
字节 b  1kb 1mb  1g t 
 echo pow(2,64);  
